Critical to the responsible and rapid translation of basic discovery to clinical trials is safety testing of vectors in a process called Toxicology. The Institute for Human Gene Therapy (IHGT) has been proactive in developing an extensive database of toxicology for a broad range of clinical applications. Dr. Joseph V. Hughes is responsible for managing the toxicology effort in collaboration with the Animal Services Unit (ASU), the Cell Morphology Core (CMC), and the Immunology Core. Toxicology represents a carefully managed and highly regulated undertaking in which protocols are developed in multiple animal species to evaluate key safety issues relevant to the use of vectors in humans. This unit conducts over 50 independent toxicology protocols per year, 20% of which involves non- human primates. The Toxicology Program will be critically important to P30 investigators as they translate basic discoveries made in animal models to proof of concept experiments in humans. Experiments are currently underway to assess vector safety in a number of applications in gene therapy relevant to genetic diseases such as hemophilia, retinitis pigmentosa, lysosomal storage diseases, inherited myopathies, and hormone replacement.